HOWTO: Fix OneDrive sync client login hangs

For the last week, the OneDrive sync client on my machine would not login. The client’s System Tray icon just sat there and said, “Signing in” forever.

Attempting to right mouse click on the SysTray icon for OneDrive (for the OneDrive for Business connection) simply revealed a mostly greyed out menu that was basically useless. In my pursuit of trying to figure out where things had gone wrong, I learned that an end user can NOT read the logs of OneDrive’s sync client. It’s binary & unintelligible. @#$%

BACKGROUND: I currently have the OneDrive sync client on my machine synchronizing:

My personal OneDrive (consumer) files from OneDrive.com

My personal OneDrive for Business files from Office 365

The SharePoint document folders for over 12 different SharePoint team sites

That last bullet is important because I rarely go directly to any of the SharePoint sites themselves via a web browser.

I usually just:

Sync documents to the SharePoint document libraries so that other people can access them via OneDrive sync client

Sync Outlook contacts to a Contacts folder in the SharePoint site via Outlook 2016

Sync a team site OneNote notebook via OneNote 2016

Note that none of these activities actually require connecting to the web-front ends of these SharePoint sites via a web browser. All login & activities are executed through the OneDrive client, Outlook 2016, and OneNote 2016.

MY FIX:After working on this for more than a week, I put the issue on the backburner because another issue arose: One of my SharePoint team sites was no longer accessible.

I discovered it was locked out and couldn’t be accessed so I contacted our IT department who unlocked it. (It’d been locked out due to not being verified for our internal compliance check.)

After that had been fixed, I looked down at the sync client and lo and behold, it’d apparently logged in and started syncing… And it was now syncing all ~300MB of data that had changed since the last time I’d been able to successfully sync to both OneDrive for Business as well as my SharePoint Team sites.

CONCLUSION: The point is this: It appears that the OneDrive sync client will NOT notify you about login failures to SharePoint document folders that you are syncing to, and because there are no logs to review, there’s no way for you to identify the reason the OneDrive sync client won’t login. It may login to your OneDrive for Business document folder… but not to the SharePoint document libraries you’re syncing as well.

So lesson learned… be sure to check that you can access all OneDrive for Business & SharePoint document libraries independently if you are having issues with the OneDrive sync client logging into OneDrive for Business.

Because it won’t tell you where your login/authentication issues are coming from.